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Class: RBS::Substitution

Relationships & Source Files
Inherits: Object
Defined in: lib/rbs/substitution.rb

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new ⇒ Substitution

[ GitHub ] 

  


# File 'lib/rbs/substitution.rb', line 12



def initialize()
  @mapping = {}
end


  







Class Method Details



  

    .build(variables, types, instance_type: nil, &block)  
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 20



def self.build(variables, types, instance_type: nil, &block)
  unless variables.size == types.size
    raise "Broken substitution: variables=#{variables}, types=#{types}"
  end

  mapping = variables.zip(types).to_h

  self.new.tap do |subst|
    mapping.each do |v, t|
      type = block_given? ? yield(t) : t
      subst.add(from: v, to: type)
    end

    subst.instance_type = instance_type
  end
end


  







Instance Attribute Details



  

    #empty?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 8



def empty?
  mapping.empty? && instance_type.nil?
end


  








  

    #instance_type   (rw)
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 6



attr_accessor :instance_type


  








  

    #mapping   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 5



attr_reader :mapping


  







Instance Method Details



  

    #+(other)  
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 66



def +(other)
  return self if other.empty?
  return other if self.empty?

  Substitution.new.tap do |subst|
    subst.mapping.merge!(mapping)

    other.mapping.each do |var, type|
      if mapping.key?(var)
        subst.add(from: var, to: self[type])
      else
        subst.add(from: var, to: type)
      end
    end
  end
end


  








  

    #[](ty)  
  



  

    

Alias for #apply.


  



  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 53



alias [] apply


  








  

    #add(from:, to:)  
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 16



def add(from:, to:)
  mapping[from] = to
end


  








  

    #apply(ty)  
    Also known as: #[]
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 37



def apply(ty)
  case ty
  when Types::Variable
    # @type var ty: Types::Variable
    mapping[ty.name] || ty
  when Types::Bases::Instance
    if t = instance_type
      t
    else
      ty
    end
  else
    ty
  end
end


  








  

    #without(*vars)  
  

  [ GitHub ]


  

  


# File 'lib/rbs/substitution.rb', line 55



def without(*vars)
  Substitution.new.tap do |subst|
    subst.mapping.merge!(mapping)
    vars.each do |var|
      subst.mapping.delete(var)
    end

    subst.instance_type = self.instance_type
  end
end